Many types of disposable absorbent articles such as disposable diapers, training pants, feminine care articles, incontinence articles, and the like, utilize a design incorporating an absorbent pad, a surge layer, a bodyside liner material, containment flaps, a liquid impervious barrier layer, and side portions that can be brought together to close the article around the wearer's body. Often, various portions of these product designs are elasticized in some way to provide a comfortable fit and a gasket function to help reduce leakage. The liquid transfer and absorbency capabilities of the absorbent system depend, in large part, on maintaining the structural integrity and characteristics of the component parts. The structure (e.g., bulk weight, density, capillary structure) of the underlying absorbent material is tailored for particular flow rates and total absorbency depending on the type of absorbent article.
The absorbency, fit, and leakage protection properties of these products are determined in large part by the capillary structure of the components making up the absorbent system, and the elastic properties of various materials used in the total construction. The capillary structure of the various absorbent components is specifically designed and it is desirable to maintain the structure during the entire time the product is being used. Currently, many types of products utilize a piecemeal approach to provide elastic properties by attaching elastic or extensible materials to other components that have little or no elastic properties. The overall effect is to provide stretch for gasketing, fit, and comfort in some portions of the product, while keeping the absorbent components in a relatively non-stretched state to maintain the capillary structure for good absorbency. With products where the entire chassis may be stretchable, the stretching of the liner and rest of the absorbent system causes the capillary structure and fluid handling properties to also change. The capillary structure would change if the absorbent components are stretched. For example, if a necked material with a given fiber and capillary structure is used as a bodyside liner material and is stretched in a direction, the fibers are forced to move and/or rotate to accommodate the stretch. This movement and/or rotation of the fibers changes the capillary structure of the necked nonwoven material. If the necked, non-stretched nonwoven had an ideal capillary structure before stretching, the stretched material will no longer have that ideal structure. In general, any changes in the dimensions of the material in width, length, or thickness will change the capillary structure.
A product design that includes elastic materials attached to non-elastic, non-extensible materials often requires a process that brings the various materials together in a rather complicated fashion, and may attach the components together in ways that ‘tie-up’, or negate, the functionality of the elastic materials in these areas of attachment. Other attachment means may reduce the functionality of the elastic components, or require more expensive components to overcome the effect of attachment to the article.
It has been found that overall extendable or elastomeric absorbent products are highly desirable for fit, comfort, and containment. It can be seen that a problem may occur in that for optimum absorbency, the product should not extend, but for fit, comfort, and containment, it should extend without the complications that arise from attaching multiple elastic and non-extensible components together. The present invention resolves this dilemma.